1. Field of the Invention
This invention relates to a method of manufacturing slide fastener products from an elongate continuous stringer chain and more particularly such a method which enables selective production of slide fasteners of different types, lengths and/or colors during a continuous automatic cycle of operation.
2. Prior Art
There are known certain methods of manufacturing slide fasteners from a continuous stringer chain without interrupting or shutting down the production line. A typical example of such method is disclosed in Japanese Patent Laid-Open Publication No. 2-74205 which teaches marking a stringer chain at certain intervals or at defective portions by punching holes which serve as a means of controlling the operation of each of the parts applying units in a slide fastener manufacturing apparatus. Such prior art method has a difficulty in that the punched out holes Ph (FIG. 10) are prone to get plugged up or otherwise marred by dusts, frayed yarns of the stringer tapes, or other foreign matters, resulting in inaccurate detection of the marks which is usually optically performed.